In many computer network environments, requests sent by a computer-based client application to an application server, such as requests to access a software application, require that the request be authenticated before the request is authorized. Such requests and their attendant responses are conveyed in accordance with a transport protocol, such as the Hypertext Transport Protocol (HTTP). The requests themselves are typically received at a request interceptor, whose job it is to receive requests, assist in request authentication and authorization, and forward authenticated and authorized requests to the requested applications. With the emergence of new protocols, such as the Session Initiation Protocol (SIP), the request interceptor must be adapted to support them, or new, protocol-specific request interceptors must be provided. Techniques for efficiently handling multi-protocol authentication and authorization in computer network environments would be advantageous, as would be techniques that take advantage of multi-protocol requests to provide new authentication and authorization paradigms.